The House Science, Space, and Technology Committee sent a letter to the head of the National Science Foundation (NSF) on Monday, demanding answers about the origins of the nearly $1 million taxpayer-funded project to track “misinformation” on Twitter.

The Truthy project, being conducted by researchers at Indiana University, is under investigation for targeting political commentary on Twitter. The project monitors “suspicious memes,” “false and misleading ideas,” and “hate speech,” with a goal of one day being able to automatically detect false rumors on the social media platform.

The web service has been used to track tweets using hashtags such as #tcot (Top Conservatives on Twitter), and was successful in getting accounts associated with conservatives suspended, according to a 2012 book co-authored by the project’s lead researcher, Filippo Menczer, a professor of Informatics and Computer Science at Indiana University.

Menczer has also said that Truthy monitored tweets using #p2 (Progressive 2.0), but did not discuss any examples of getting liberal accounts suspended in his book.

“The Committee and taxpayers deserve to know how NSF decided to award a large grant for a project that proposed to develop standards for online political speech and to apply those standards through development of a website that targeted conservative political comments,” wrote Chairman Lamar Smith, R-Texas, in a letter to NSF Director France Cordova.